I think you'd need a lens arrangement to make the image appear inside the mirror. It's not just related to binocular vision either, if you have focus a camera on an object appearing in a (flat) mirror, the focal distance is going to be pretty close to the distance from the camera to the mirror + the distance from the mirror to the object.

Now, I don't think you need to get this exactly right, but if you could make the video image appear at a focal depth close to to the length from the mirror to the back window, it would be a lot easier on the eyes than the image appearing at a focal depth of about a foot. I'm not good with optics though, so don't ask me how to do that! :D